sounds as if possibly your internet is dropping .... or your hdd is thrashing - maybe because it's getting full - or maybe the temp folder needs emptying
(tools | internet options | general | history
sometimes when my virus scanner kicks in ie does the same.
(and sometimes it just does it out of badness!)
If you want to try firefox - before you commit
d/l a self contained version from
http://portableapps.com/suite
and see what you think of it
(personally I don't like it)